In Florida, the species that causes most red tides is Karenia brevis. This organism produces toxins that can affect the central nervous system of aquatic organisms such as fish and marine mammals. Red tide toxins also pose a human health risk.

The toxins can aerosolize and be carried to beaches with onshore winds, leading to respiratory irritation in people.

Toxins can accumulate in shellfish and result in illnesses if contaminated shellfish are consumed. Shellfish harvesting areas are closed when blooms are present.

Florida Fish and Wildlife Conservation Commission (FWC) researchers are currently monitoring two blooms along Florida’s Gulf coast, one located in northwest Florida and the other in southwest Florida.

“We confirmed the presence of both blooms in September, and they have persisted since that time,” said Alina Corcoran, FWC research scientist.

“The bloom in the Panhandle is currently affecting Santa Rosa, Okaloosa, Walton, Bay and Gulf counties. In southwest Florida, patchy blooms have been confirmed along Pinellas, Manatee, Sarasota, Charlotte and Lee counties. Extensive fish kills and respiratory irritation have been associated with the bloom in the Panhandle but in southwest Florida the effects have been less.”

Red tide public health tips:

People in a red tide area can experience varying degrees of eye, nose and throat irritation. When a person leaves an area with a red tide, symptoms usually go away.

People with severe or chronic respiratory conditions such as asthma or chronic lung disease are cautioned to avoid areas with active red tides.

In some red tides, dead fish wash ashore; during these conditions it is advised that beachgoers avoid swimming in water where dead fish are present.

Pet owners are advised that red tide poses a risk to animals brought to the beach. If a pet swims in a red tide patch at the beach, rinse off its fur and paws as soon as possible with fresh water. Also, do not let pets eat fish or drink water from the red tide.

Recreational harvesting of bivalve mollusks such as hard clams, oysters and mussels from approved shellfish harvesting areas is banned during red tide closures. To determine whether harvesting of shellfish is permitted in an area, visit the Florida Department of Agriculture and Consumer Services, Division of Aquaculture website.

FWC researchers work closely with partners, including Mote Marine Laboratory, the University of South Florida, Department of Health, Department of Agriculture and NOAA, to track blooms, share information and develop products that help to inform both citizens and scientists about bloom conditions.

“Citizen scientists play a vital role in tracking blooms. Volunteers can provide the majority of water samples for bloom tracking in regions like the Panhandle,” said Corcoran.

For updated red tide status reports, to track blooms or learn more about red tide, visit MyFWC.com/RedTide. To report fish kills to the FWC, contact the Fish Kill Hotline at 800-636-0511 or submit a report online.